CVE-2026-41650Public exploitNetwork attack vector

XML injection via unescaped comment and CDATA delimiters

Published May 7, 2026 · Updated May 7, 2026

XML injection in Natural Intelligence fast-xml-parser before 5.7.0 allows remote attackers to alter generated XML via crafted data. XMLBuilder's buildTextValNode method inserts comment and CDATA values between literal delimiters without neutralizing embedded termination sequences. Exploitation requires an application to place attacker-controlled data in those elements and a downstream system or browser to process the generated document, enabling document manipulation or script execution.

CVSS severity6.1
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

XML injection in Natural Intelligence fast-xml-parser before 5.7.0 allows remote attackers to alter generated XML via crafted data. XMLBuilder's buildTextValNode method inserts comment and CDATA values between literal delimiters without neutralizing embedded termination sequences. Exploitation requires an application to place attacker-controlled data in those elements and a downstream system or browser to process the generated document, enabling document manipulation or script execution.

The record

CVE
CVE-2026-41650
Published
May 7, 2026
Updated
May 7, 2026
Vendor
Natural Intelligence
Product
fast-xml-parser
Classifications
CWE-91, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2026CVE publishedPublication date reported by the CVE source.
  2. May 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 5.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Natural Intelligence · fast-xml-parserversion=< 5.7.0

Published CVSS scores

6.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-91XML Injection (aka Blind XPath Injection)
T1059.007Command and Scripting Interpreter JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo